Anti-chattering air supported cleaner



Nov. 26, 1957 J. c. MONTGOMERY ANTI-CHATTERING AIR SUPPORTED CLEANER 2 Sheets-Sheet 1 Filed Oct. 8, 1954 O 6 O 6 w 8 2 q .m l F O 5 a 7. 4 \3/ Q .5 0 J/ 4 2 kf w 1K 6 J. 5

Nov. 26, 1957 J c, MONTGOMERY 2,814,064

ANTI-CHATTERING AIR SUPPORTED CLEANER Filed Oct. 8, 1954 2 Sheets-Sheet 2 United States Patent Office Patented Nov. 26, 1957 2,814,064 ANTI-CHATTERING AIR SUPPORTED CLEANER John C Montgomery, North Olmsted, Ohio, assignor to The Hoover Company, North Canton, Ghio, a corporation of (Milo Application October 8, 1954, Serial No. 461,076 Claims. (Cl. -326) This invention relates to the art of suction cleaners and is particularly directed to a suction cleaner of the general type disclosed and claimed in the copending application of Curtis C. Coons and John C. Montgomery, Serial Number 418,512, filed March 25, 1954, for Air Supported Cleaner, now Patent No. 2,780,826, dated February 12, 1957.

It is a particular object of the present invention to provide a suction cleaning device of the type disclosed and claimed in the aforesaid application modified to prevent chattering or rocking of the suction cleaner body while supported on an'air cushion.

It is a further object of the present invention to provide a suction cleaner including an exhaust air trapping device on the underside of the cleaner which forms an air bearing or air cushion upon which the weight of the cleaner is substantially supported in order to render the cleaner movable across a supporting surface in re sponse to forces of extremely small magnitude. The air supporting structure characterizing a cleaner of the character stated immediately above, is provided with a unique rim structure forming a calibrated air exhaust port so proportioned as to maintain a lifting force applied to the underside of the cleaner substantially equal to its weight and positioned within an air entrapping and directing ring rigidly connected to the cleaner body which diverts the lifting air through an exhaust diflusing structure after the air has performed its supporting-function.

It is another object of the present invention to provide .an air supported suction cleaner having an annular rim on its underside defining the peripheral limit of an air cushion or air bearing entrapping space wherein the rim is segregated into inner and outer sections and in which the inner section has a vertical elevation above a supporting plane slightly greater than the elevation of the outer portion of the rim to form a calibrated escape port for air entrapped within the air cushion or air bearing forming structure.

-It is a principal object of the present invention to provide a suction cleaner incorporating an air cushion or an air bearing supporting structure wherein means are provided to insure that air exhausting from the air hearing will flow in a thin calibrated stream around the entire periphery of the supporting structure and will then be diverted through a diffuser whereby the cleaner is uniformly supported and is prevented from rocking or chattering upon a supporting surface and is also characterized by the absence of laterally-directing air currents discharging beneath the cleaner across the surface of a supporting rug, carpet, or the like.

Other objects and advantages of the invention will be come apparent as the description proceeds when taken in connection with the accompanying drawing wherein:

Figure 1 is a vertical elevational view, partly in section, of a cleaner embodying my invention and illustrating the position of the apparatus when'the cleaner motor is de-energized;

Figure 2 is a fragmentary vertical sectional View of the apparatus of Figure 1, taken along the line 22 of Figure 4 and looking in the direction of the arrows, illustrating the conditions obtaining when the cleaner motor is energized and the air bearing is effective;

Figure 3 is a bottom plan view of the apparatus of Figure 1; and

Figure 4 is a sectional view of the apparatus of Figure 2, taken along the line 4-4 and looking in the direction of the arrows.

Referring now to the drawing in detail, and first to Figure 1 thereof, the illustrated embodiment of my apparatus comprises a substantially cylindrical and slightly upwardly tapered main casing 1 which houses the filtering and power driving mechanism as will be explained hereinafter. Casing 1 is open at its top and bottom. The top wall of the casing 1 is defined by inwardly-directed stepped shoulders 2 and 3. A slightly dome-shaped cover member 4 is secured to the casing l by means of a hinge structure 5 and includes an inwardly-turned base flange 6 which is adapted to rest upon the shoulder 2 when the cover is in the closed position illustrated in Figure l. A toggle latch structure of known construction, indicated generally by the reference character 7, is mounted on the casing 1 diametrically opposite the hinge 5 and is engagable with a latch keeper 8 in the assembled closed position of the parts illustrated in Figure 1 to maintain the flange 6 in firm engagement with the seat 2. A bail type carrying handle 10 is pivotally secured to handle brackets 11 attached to the upper portion of the cover 4. The central portion of the cover 4 is open and carries a suction hose connecting conduit member 13 projecting inwardly of the structure formed by the casing 1 and cover 4. The member 13 is provided with a laterally-directed peripheral flange 14 which is secured to the member 4 around the periphery of the central opening thereof by riveting or other suitable means. The member 13 is provided with an interior circumferential channel 15 for a purpose to be described.

Suction cleaners of the type here under consideration are customarily utilized with various types of dusting tools such as the tool illustrated generally by the reference character 18 which is connected to an elongated flexible suction hose 19 which in turn is connected to an elbow conduit structure 20 swivelly mounted in the inlet conduit 13 to rotate approximately about a vertical axis so that the tool 18 may be utilized in any angular position with respect to the cleaner casing without rotating the same on its axis. The member 20 is detachably secured in the inlet conduit fitting 13 by means of a latch member 22 engaging within the channel 15 as illustrated in Figure 1. A spring button member 23 is provided on the member 20 for the purpose of retracting the latch 22 from the channel 15 to separate the elbow 2% from the cover 4 if desired.

An imperforate ring member 25 is secured to the casing 1 interiorally thereof approximately just below the center line. The ring member 25 is provided with an inwardlydirected seating flange 26defining the inner periphery thereof and forming a seat for cushioning gaskets 27 which grip a radially-extending supporting flange 28 on a power plant unit consisting of a motor 29 and a suction fan structure having an air inlet 31. The fan structure is the conventional type of multiple rotor high suction fan which are utilized'in suction cleaners of this general type. The fan structure 30 is overlaid by a perforated metallic supporting and air passing member 32 which rests upon the uppersurface of the gasket 27. The gasket 27, motor flange 28 and screen 32 are rigidly secured to the flange 26 by means of studs 34 which pass through the screen member, the gasket and theflange 26 to thread into nuts 35 secured as by welding or the like to the undersurface of flange 26. The power plant structure and ring member 25 divide the interior of the casing 1 into an upper low pressure or suction chamber 37 and lower motor and high pressure discharge chamber 38. The power plant structure comprising the motor 29 and fan 30 is of the conventional type used in suction cleaners wherein the air discharged from the fan structure flows through the common motor fan housing and passes over the motor to cool the same before discharging into the chamber 38.

The bottom edge of the casing 1 is defined by an inwardly-directed annular supporting shoulder 40 which in turn is connected to an inwardly-facing, higher level annular supporting flange 41. The bottom portion of the high pressure chamber 38 is defined by a dome-shaped member 42 having an inverted peripheral flange underlying the flange 41 to which it is secured in a manner to be described hereinafter. The central portion of the dome 42 is open and is provided with an exhaust fitting 44 similar to fitting 13 designed to receive the elbow 20 in order to convert the apparatus to blowing operation when desired. When used as a suction cleaner, however, air under pressure discharging from the power plant into the chamber 38 exhausts through the open passageway 44 into the space below the dome 42 as will be apparent.

The structure so far described is maintained elevated above the supporting surface here indicated as a rug or carpet 45 by structures to be described.

The supporting structure comprises an outer, slightly curved but generally conical member 46 having the upper end thereof defined by an inwardly-directed portion 47 engaging and underlying the ring 40 and terminating in an inwardly-directed flange 48 underlying the flange 43. The members 41, 43 and 48 are rigidly secured together by means of studs 49.

The supporting structure also includes an inner memher which is provided with an internal flange 50 shaped complementally to the dome 42 and secured thereto by studs 51. The outer portion of flange 50 joins an outwardly and downwardly-directed conical shaped section 52 the lower end of which joins an inwardly and downwardly-directed conical section 53 terminating in a flat support ring or flange 54. The support ring 54 terminates in an upwardly-directed flange 56 joined at its upper end by spaced webs 57 (see Figure 3) to the upper end of a vertical flange 58 spaced from the flange 56 to form an annular air passageway 59 therebetween. The lower end of flange 58 joins a horizontal support ring 60 which is spaced from the support ring 54 and projects downwardly approximately 0.015 of an inch below the lower surface of the support ring 54. The outer edge of the flange 60 terminates in an upwardly-directed flange 61 which is received within and secured to the lower edge of the member 46.

The dimension 0.015", as stated, is only approximate and will vary with different cleaners depending upon their weight, the normal air flow through them and other factors. The dimension 0.015 has been found satisfactory with some cleaners and a dimension as high as 0.025" has also been used. Thus the vertical distance between the lower edges of rings 54 and 60 may vary but must be designed to be proper with the particular cleaner under consideration.

The upper portion of the member 46 is provided with a plurality of peripheral air discharge ports 63 the lower edges of which are defined by short inwardly-turned flanges 64 forming upper stops for a mass of sound-insulating material 65 having a low air flow resistance. The material 65 rests between the underside of flange 64 and the upper surface of the web 57.

It is to be noted that the center of gravity of the cleaner is low and positioned substantially centrally of the casing 1 so that the cleaner is stable both when idle and when it is air supported.

The constructions described hereinabove constitute an important improvement upon the invention disclosed and claimed in the application of Coons and Montgomery identified above. The air supported cleaner structure characteristic of the Coons and Montgomery invention may be moved across a supporting surface as a result of a scarcely perceptible force supplied to the suction hose. However, on certain types of surfaces it has been observed that air supported cleaners of that type exhibit a tendency to chatter; that is, the air escaping under the trapping ring tends to make an irregular path at times and to produce a hardly perceptible rocking motion of the cleaner body but which, nevertheless, produces an audible chatter upon the supporting surface. Also, air supported cleaners wherein the air is permitted to discharge laterally beneath the supporting ring across the surface of the carpet or other surface covering have an undesirable side effect in that the air blows and scatters loose litter which may happen to be resting upon the carpet in the immediate vicinity of the cleaner itself. It is a further characteristic of devices of the foregoing character that the air escaping under the support ring may at times produce an objectionable sibilant noise.

The improvement on the Coons and Montgomery invention forming the subject matter of this application successfully overcomes all of the foregoing difiiculties.

In the use of the invention herein disclosed all air used in the cleaning process exhausts under the surface 54 to support the cleaner upon an air hearing. The elevation of the surfaces 54 and 60 is made approximately 0.015" different to entrap the escaping air from the air bearing and to provide lateral stability of the cleaner. The surface 54 is raised slightly above the carpet by the air passing thereunder as is most clearly shown in Figure 2. The surface 60 remains in light contact with the nap of the carpet to form an encircling trap ring for air exhausting under surface 54. The exhausting cushioning air is diverted by the surface 58 through the ports 59 whence it passes through the sound deadening material 65 and exhausts in a diffused low velocity stream around the perimeter of the cleaner through the ports 63 around the periphery of the cleaner. The air stream exhausting through the ports 63 is well above the supporting surface and of low velocity unobjectionable air flow. The material 65 serves to deaden the sibilant noise produced by flow of air under the surface 54 and also to muflle airborne noises produced by the motor and fan unit. Due to the light contact which continuously exists between the surface 60 and the supporting carpet, the cleaner will rise and maintain itself evenly upon the surface without chartering or rocking motion. The annular passageway 70, shown most clearly in Figure 2, under the surface 54 in effect forms a restricted throat or orifice for discharging air from the supporting cushion beneath the dome 42 and within the ring 52-53. The 0.015" difference in elevation between the parts 54 and 60 has been found to be approximately correct to provide an orifice which will accommodate the full flow or air from the cleaner without undue back pressure while maintaining a sufficient pressure beneath the dome 42 to counterbalance substantially the entire weight of the cleaner structure so that the very light engagement between surface 60 and the nap or pile of the carpet 45 is insuflicient to impose a significant frictional drag on the cleaner as it is moved bodily upon a supporting surface. That is, a very slight force applied to the hose 20 will cause the cleaner to move in any direction on the supporting surface on an air bearing which is substantially frictionless, in fact, a slight push applied to the side of the canister 1 in any direction is sufiicient to cause the cleaner to move freely several feet across a supporting carpet. Additionally, the engagement between the upper surface of the pile of the carpet and the surface 60 does not produce any frictional reaction force of a magnitude tending to overturn the cleaner when a pull is applied to hose 19.

My invention is particularly characterized in that an air supported cleaner is formed with an entrapping ring on its underside which forms the peripheral walls of the air body forming the air cushion or bearing. The upper and lower walls of the cushion or bearing being formed respectively by the underside of the cleaner and the supporting surface. The air cushion or hearing is provided with a very thin annular discharge port from which the air from the bearing exhausts to a diffusing structure and is prevented from blowing directly across the carpet by a very slightly lower outer ring which just grazes the supporting surface so as to maintain the cleaner in stable condition and to prevent lateral discharge of air therefrom. In its simplest conception my invention consists of a cleaner including an air bearing structure and provided with surface egaging means projecting slightly below the discharge throat of the air cushion to graze lightly upon the supporting surface so as to prevent chattering or rocking action upon the part of the cleaner body.

When the cleaner is first started the exhaust air will escape beneath the face 54 as the pressure builds up Within the air pocket and thus prevent the cleaner from starting to vibrate until it is completely air supported. When a pull is then applied to the hose to move the cleaner about the cleaner may tilt slightly and raise one edge of the support above the supporting surface and again the air will escape from beneath the face 54 at its high side and prevent the cleaner from starting to vibrate.

While I have illustrated and described the invention in considerable detail, it is to be understood that various changes may be made in the arrangement, proportion and construction of parts without departing from the spirit of the invention or the scope of the appended claims.

Iclaim:

1. In a suction cleaner having a casing, a suction producing unit in the casing, means on the casing forming an air chamber on the underside of the casing open to the supporting surface, means for leading exhaust air from the suction producing unit to the air chamber, said air chamber forming means including an annular Wall member defining the peripheral extent of the air chamber, a second annular wall member rigidly attached to said casing and spaced around the first annular wall member and forming an air exhaust throat therewith, an air diffusing structure for exhausting air from the throat and the second annular wall member having the lower edge thereof projecting slightly below the lower edge of the first annular wall member and normally supporting the lower edge of said first annular wall member slightly above the lower edge of said second annular Wall member when the cleaner is idle and rests on a supporting surface whereby the second annular wall member retains light contact with a supporting surface when the cleaner is substantially entirely supported upon an air bearing or cushion to insure discharge of air through the throat.

2. In a suction cleaner having a casing, a suction air pump in the casing connected to induce a flow of cleaning air into said casing, the combination of supporting means on the casing including an annular peripheral portion defining the outer perimeter of an air space having a substantial area on the underside of the casing and open to a supporting surface within the annular portion and means for supplying air under pressure from the air pump to the said air space to form a weight supporting air cushion beneath the casing, an annular wall rigidly attached to said casing surrounding and spaced from the annular peripheral portion, the lower end of the annular wall projecting slightly below the lower edge of the peripheral portion to engage a supporting surface and stabilize the casing on the air cushion and to maintain the lower edge of said peripheral portion slightly above the supporting surface when the cleaner is idle, and a diffus ing and exhaust structure open to the space between the annular wall and peripheral portion for exhausting air escaping from the air cushion,

3. In a suction cleaner having a casing including air inlet and outlet ports, means in the casing for'produ'cing a flow of cleaning air into the casing and for discharging such air under pressure from the outlet port, the combination of means for entrapping air under pressure dischargingfrom 'the discharge port between the casing and asupporting surface and for restricting the flow of air from beneath said casing, the area of the supporting surface encompassed by said air entrapping means being so related to the weight of the cleaner and to the quantity of air discharged from said discharge port that the pressure of the entrapped air serves to support the weight of the cleaner and'means rigid with said casing and projecting slightly below the lower edge of the air 'entrapping means to maintain contact with the supporting surface to prevent chattering of the air supporting means when the cleaner is in operation and supported on an air cushion and maintain the lower edge of the air entrapping means above the supporting surface when the cleaner is idle.

4. In a suction cleaner comprising a casing, an air pump in the casing to produce a fiow of cleaning air into said casing and a drive motor for the air pump in the casing, the combination of an annular skid for supporting the casing on a supporting surface and enclosing'an air space having a substantial area below the casing and exposed to the supporting surface, and means for leading air under pressure discharged by the air pump to the air space, said skid being formed to restrict the flow of air from said air space, the area of the supporting surface enclosed by said skid being so related to the weight of the cleaner and to the quantity of air led into said air space that the casing is supported on an air cushion, and means rigid with the casing projecting slightly below the skid to engage the supporting surface to balance the casing evenly on the air cushion whereby air exhausts evenly around the periphery of the skid and to support the skid slightly above the supporting surface to maintain a slight gap between the skid and supporting surface when the cleaner is idle.

5. In a suction cleaner having a casing, a suction air pump in the casing connected to induce a flow of cleaning air into said casing, the combination of supporting means on the casing including an annular peripheral portion defining the outer perimeter of an air space having a substantial area on the underside of the casing and open to a supporting surface within the annular portion and means for supplying air under pressure from the air pump to the said air space, said annular portion being formed to restrict the flow of air from said air space, the area of the supporting surface enclosed by said annular portion being so related to the weight of the cleaner and to the quantity of air supplied to said air space to form a cleaner Weight supporting air cushion beneath the casing and means rigid with the casing projecting slightly below the lower edge of the annular peripheral portion to maintain light contact with a supporting surface to maintain the balance of the casing on the air cushion and to maintain the lower edge of said annular peripheral portion above the supporting surface when the cleaner is idle.

6. In a suction cleaner having a casing, a suction producing unit in the casing, the combination of means on the underside of the casing forming an air chamber open to a supporting surface, means to conduct exhaust air under pressure into the air chamber to support the cleaner on an air bearing or cushion, said air chamber forming means including a downwardly extending annular member defining the peripheral wall of the air chamber adjacent the supporting surface, said annular member being formed to restrict the flow of air from said chamber, the area of the supporting surface within said peripheral Wall being so related to the weight of the cleaner and to the quantity of air conducted to said chamber that exhaust air escapes from the air chamber beneath the annular member to support the casing on a cushion of air, and means rigid with the casing projecting slightly below the annular memher to maintain light contact with a supporting surface when the casing is air supported to prevent rocking or chattering of the casing and to maintain said annular member above the supporting surface when the cleaner is idle.

7. Apparatus according to claim 6 wherein the means projecting below the annular member comprises a ring member surrounding the annular member in spaced relation thereto to form an annular upwardly-directed exhaust port between the annular and ring members.

8. Apparatus according to claim 7 wherein the casing includes a shroud structure overlying and encasing the exhaust port, a mass of sound deadening material is housed in the shroud over the exhaust port, and the shroud is provided with a plurality of circumferentially spaced exhaust ports positioned to receive air which has traversed the sound deadening material.

9. In a suction cleaner having a casing including an air inlet port and an air outlet port, and means in said casing for producing a flow of air into said inlet port and for discharging air under pressure from said outlet port, said casing having a supporting base normally supporting the cleaner in a stable position on a supporting surface when said air flow producing means is not in operation, said base including a downwardly facing portion adapted to coact with a supporting surface to encompass a substantial area thereof and to restrict the flow of air from the encompassed area between said portion and the supporting surface, said outlet port being arranged to discharge air under pressure beneath said base within the confines of said downwardly facing portion, the area of the supporting surface encompassed by said downwardly facing portion being so related to the weight of the cleaner and to the quantity of air discharged beneath said base that the air under pressure reacts between said casing and the supporting surface to form a supporting cushion of air which serves to support the weight of the cleaner the center of gravity of the cleaner being so related to the area encompassed by said downwardly facing portion and to the horizontal force necessary to propel the cleaner along the supporting surface when the cleaner is supported on said cushion that the cleaner may be propelled about in a stable condition by the application of the necessary horizontal force to the cleaner and means rigid with said casing projecting slightly below said downwardly facing portion to maintain light contact with the supporting surface when the casing is air supported to prevent rocking or chattering of the casing and to maintain said downwardly facing portion above the supporting surface when the cleaner is not in operation.

10. In a suction cleaner including a casing having an inlet port, suction creating means within said casing, said casing having a supporting base adapted to encompass a substantial area of the supporting surface upon which the cleaner rests to support the cleaner in a stable position, at least the periphery of said base being normally in contact with the supporting surface when the cleaner is not in use and means for supplying air under pressure beneath said base, said casing being formed to restrict the flow of air from beneath said base, the area of the supporting surface encompassed by said base being so related to the weight of the cleaner and to the quantity of air supplied beneath said base that the air under pressure reacts between said base and the area of the supporting surface encompassed by said base to form a supporting cushion of air which serves to support the weight of the cleaner and means rigid with said casing projecting slightly below said base to maintain light contact with the supporting surface when the casing is air supported to prevent rocking or chattering of the casing and to maintain said base above the supporting surface when the cleaner is not in operation.

References Cited in the file of this patent UNITED STATES PATENTS 978,916 Matchette Dec. 20, 1910 1,083,408 Matchette Jan. 6, 1914 2,332,208 Dow Oct. 19, 1943 2,439,182 Nufier et al. Apr. 6, 1948 2,652,902 Sheahan Sept. 22, 1953 2,743,787 Seek May 1, 1956 FOREIGN PATENTS 571,465 France Feb. 2, 1924 279,858 Great Britain Mar. 8, 1928 524,095 Germany May 21, 1931 

